A giant hidden planet with a gravitational pull so strong that it would literally cause the earth to turn upside down is on course to destroy us. Planet X has caused mass extinctions in the past. Some are preparing for the next celestial Armageddon.

Smallpox, the Black Death, Spanish Flu, Zika. History has taught us that when it comes to new viruses, humankind is still vulnerable, despite modern medicine. Meet people who are determined to survive the next global pandemic.